I am using a generic tcp connect on hpux 11i with an ipv6 address.
I am able to make the connection with an ipv4 address.

host_addr = InetAddress.getByName(host);
host_sock_addr = new InetSocketAddress(host_addr, port);
       try
       {
           socket = new Socket();
       }
       catch (SocketException e)
       {
          //error
       }

       try
       {
           socket.connect(host_sock_addr, 1000);
       }
       catch (SocketException e)
       {
          System.out.println(" err "+e.toString() + "  "
+Err.SOCKET_CONNECT_ERR );
           return retval;
       }

output:
java.net.SocketException: Protocol family unavailable  56